2 files changed, 49 insertions, 58 deletions

diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index ca1d27a0d6a6..077f65321b5e 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -264,10 +264,34 @@ extern void arch_arm_kprobe(struct kprobe *p);
 extern void arch_disarm_kprobe(struct kprobe *p);
 extern int arch_init_kprobes(void);
 extern void show_registers(struct pt_regs *regs);
-extern kprobe_opcode_t *get_insn_slot(void);
-extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
 extern void kprobes_inc_nmissed_count(struct kprobe *p);
 
+struct kprobe_insn_cache {
+        struct mutex mutex;
+        struct list_head pages; /* list of kprobe_insn_page */
+        size_t insn_size;       /* size of instruction slot */
+        int nr_garbage;
+};
+
+extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c);
+extern void __free_insn_slot(struct kprobe_insn_cache *c,
+                             kprobe_opcode_t *slot, int dirty);
+
+#define DEFINE_INSN_CACHE_OPS(__name)                                   \
+extern struct kprobe_insn_cache kprobe_##__name##_slots;                \
+                                                                        \
+static inline kprobe_opcode_t *get_##__name##_slot(void)                \
+{                                                                       \
+        return __get_insn_slot(&kprobe_##__name##_slots);               \
+}                                                                       \
+                                                                        \
+static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
+{                                                                       \
+        __free_insn_slot(&kprobe_##__name##_slots, slot, dirty);        \
+}                                                                       \
+
+DEFINE_INSN_CACHE_OPS(insn);
+
 #ifdef CONFIG_OPTPROBES
 /*
  * Internal structure for direct jump optimized probe
@@ -287,13 +311,13 @@ extern void arch_optimize_kprobes(struct list_head *oplist);
 extern void arch_unoptimize_kprobes(struct list_head *oplist,
                                     struct list_head *done_list);
 extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
-extern kprobe_opcode_t *get_optinsn_slot(void);
-extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty);
 extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
                                         unsigned long addr);
 
 extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
 
+DEFINE_INSN_CACHE_OPS(optinsn);
+
 #ifdef CONFIG_SYSCTL
 extern int sysctl_kprobes_optimization;
 extern int proc_kprobes_optimization_handler(struct ctl_table *table,
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 6e33498d665c..9e4912dc5559 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -121,12 +121,6 @@ struct kprobe_insn_page {
         (offsetof(struct kprobe_insn_page, slot_used) + \
          (sizeof(char) * (slots)))
 
-struct kprobe_insn_cache {
-        struct list_head pages; /* list of kprobe_insn_page */
-        size_t insn_size;       /* size of instruction slot */
-        int nr_garbage;
-};
-
 static int slots_per_page(struct kprobe_insn_cache *c)
 {
         return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t));
@@ -138,8 +132,8 @@ enum kprobe_slot_state {
         SLOT_USED = 2,
 };
 
-static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_slots */
-static struct kprobe_insn_cache kprobe_insn_slots = {
+struct kprobe_insn_cache kprobe_insn_slots = {
+        .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex),
         .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages),
         .insn_size = MAX_INSN_SIZE,
         .nr_garbage = 0,
@@ -150,10 +144,12 @@ static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c);
  * __get_insn_slot() - Find a slot on an executable page for an instruction.
  * We allocate an executable page if there's no room on existing ones.
  */
-static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
+kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
 {
         struct kprobe_insn_page *kip;
+        kprobe_opcode_t *slot = NULL;
 
+        mutex_lock(&c->mutex);
  retry:
         list_for_each_entry(kip, &c->pages, list) {
                 if (kip->nused < slots_per_page(c)) {
@@ -162,7 +158,8 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
                                 if (kip->slot_used[i] == SLOT_CLEAN) {
                                         kip->slot_used[i] = SLOT_USED;
                                         kip->nused++;
-                                        return kip->insns + (i * c->insn_size);
+                                        slot = kip->insns + (i * c->insn_size);
+                                        goto out;
                                 }
                         }
                         /* kip->nused is broken. Fix it. */
@@ -178,7 +175,7 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
         /* All out of space.  Need to allocate a new page. */
         kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL);
         if (!kip)
-                return NULL;
+                goto out;
 
         /*
          * Use module_alloc so this page is within +/- 2GB of where the
@@ -188,7 +185,7 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
         kip->insns = module_alloc(PAGE_SIZE);
         if (!kip->insns) {
                 kfree(kip);
-                return NULL;
+                goto out;
         }
         INIT_LIST_HEAD(&kip->list);
         memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c));
@@ -196,19 +193,10 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c)
         kip->nused = 1;
         kip->ngarbage = 0;
         list_add(&kip->list, &c->pages);
-        return kip->insns;
-}
-
-
-kprobe_opcode_t __kprobes *get_insn_slot(void)
-{
-        kprobe_opcode_t *ret = NULL;
-
-        mutex_lock(&kprobe_insn_mutex);
-        ret = __get_insn_slot(&kprobe_insn_slots);
-        mutex_unlock(&kprobe_insn_mutex);
-
-        return ret;
+        slot = kip->insns;
+out:
+        mutex_unlock(&c->mutex);
+        return slot;
 }
 
 /* Return 1 if all garbages are collected, otherwise 0. */
@@ -255,11 +243,12 @@ static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c)
         return 0;
 }
 
-static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c,
-                                       kprobe_opcode_t *slot, int dirty)
+void __kprobes __free_insn_slot(struct kprobe_insn_cache *c,
+                                kprobe_opcode_t *slot, int dirty)
 {
         struct kprobe_insn_page *kip;
 
+        mutex_lock(&c->mutex);
         list_for_each_entry(kip, &c->pages, list) {
                 long idx = ((long)slot - (long)kip->insns) /
                                 (c->insn_size * sizeof(kprobe_opcode_t));
@@ -272,45 +261,23 @@ static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c,
                                         collect_garbage_slots(c);
                         } else
                                 collect_one_slot(kip, idx);
-                        return;
+                        goto out;
                 }
         }
         /* Could not free this slot. */
         WARN_ON(1);
+out:
+        mutex_unlock(&c->mutex);
 }
 
-void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
-{
-        mutex_lock(&kprobe_insn_mutex);
-        __free_insn_slot(&kprobe_insn_slots, slot, dirty);
-        mutex_unlock(&kprobe_insn_mutex);
-}
 #ifdef CONFIG_OPTPROBES
 /* For optimized_kprobe buffer */
-static DEFINE_MUTEX(kprobe_optinsn_mutex); /* Protects kprobe_optinsn_slots */
-static struct kprobe_insn_cache kprobe_optinsn_slots = {
+struct kprobe_insn_cache kprobe_optinsn_slots = {
+        .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex),
         .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages),
         /* .insn_size is initialized later */
         .nr_garbage = 0,
 };
-/* Get a slot for optimized_kprobe buffer */
-kprobe_opcode_t __kprobes *get_optinsn_slot(void)
-{
-        kprobe_opcode_t *ret = NULL;
-
-        mutex_lock(&kprobe_optinsn_mutex);
-        ret = __get_insn_slot(&kprobe_optinsn_slots);
-        mutex_unlock(&kprobe_optinsn_mutex);
-
-        return ret;
-}
-
-void __kprobes free_optinsn_slot(kprobe_opcode_t * slot, int dirty)
-{
-        mutex_lock(&kprobe_optinsn_mutex);
-        __free_insn_slot(&kprobe_optinsn_slots, slot, dirty);
-        mutex_unlock(&kprobe_optinsn_mutex);
-}
 #endif
 #endif